U.S. Pat. No. 5,281,585, describes fibrinogen receptor antagonists. According to the procedure described in U.S. Pat. No. 5,281,585, the compound: ##STR2## is prepared according to a 17-step procedure which requires the use of expensive reagents and numerous chromatography steps, and gives a &lt;3% overall yield (see columns 63 to 67).
The preparation described in U.S. Pat. No. 5,281,585 involves use of 4-piperidineethanol as a starting material, and a nine step procedure leading to the intermediate ##STR3## which is thereafter modified to produce various fibrinogen receptor antagonists.
According to the present invention, an important new class of compounds, ##STR4## useful as intermediates for preparing numerous fibrinogen receptor antagonists described in U.S. Pat. No. 5,281,585 is prepared according to a two step process using commercially available starting materials.